Celebrity couples: They are good-looking, loved up and know how to work it on the red carpet, but there’s an increasing number of A-listers getting X-rated when it comes to Public Displays of Affection.

For Justin Bieber & girlfriend Selena Gomez, a day at the beach turned into something of a love-in, but they are not alone. Many celebs have become experts in all types of public affection, so here’s a selection of my favorites:

First up and with plenty of cringe factor is The Steamy Smooch: Will Smith & wife Jada Pinkett-Smith were caught on a Jumbotron going for a Hollywood kiss at a basketball game, while J-Lo and Casper Smart have been snapped smooching anywhere and everywhere.

The Passionate Peck: Restrained and reassuring. David Beckham kissed Victoria’s nose after receiving his Order of the British Empire, while President Barack Obama seems to prefer the First Lady’s forehead.

The United Front is a favorite of Tom Cruise and Katie Holmes: They love the show of solidarity, but Brad and Angelina manage to pull it off with a few more hands.

The Grope: Justin Timberlake and Mila Kunis are offenders. Perhaps they went a bit too far at the MTV awards, thankfully it was tongue-in-cheek (they aren’t even a couple.) Brad Pitt was a little subtler at a film premiere, reaching for Angie’s derriere as they were photographed upfront.

Of course it’s not just celebrities displaying their affection for each other, so how far would you go?

You may find yourself cringing when you see your favorite celebs and their wandering hands, but new research actually shows that when we see people kiss and cuddle in public, it triggers positive emotions in the brain, leaving us with that warm and fuzzy feeling inside.

And if that’s the case, well I say, smooch away!

Just recently we’ve seen Reese Witherspoon sitting next to her ex, Ryan Philippe at their son’s soccer game. Then there was Charlie Sheen, seen walking and smiling alongside his ex, Denise Richards. Many celebrity exes are on friendly terms, seemingly integrating their past into their present lives with ease.

So Why Are Celebrities Friends With Their Exes?

Celebrities are bound by certain rules. Even when children aren’t involved, many will feel ‘forced’ to remain friends with exes. Hollywood is a small town. They run into each other at public events; many share the same management; and will even be up for the same movies (think Cameron Diaz and Justin Timberlake in Bad Teacher – and if you’ve seen that film it’s probably a decision they both regret). Then there’s the rather huge issue of the paparazzi capturing their every move.

For the sake of their public image, celebrities need to be seen to be pleasant with each other. It makes good (business) sense. But what about non-celebrities…should you really be friends with an ex? Or is it better to leave the past where it belongs?

Here Are My Tips To Help You Decide Whether And How To Stay Friends With An Ex.

1. Ask yourself why you want to be friends. Whether or not you stay friends with an ex really depends on key factors in the relationship, like how serious the relationship was, and the reason for the split (for example, if a third party was involved or if the relationship simply ran its course). Bare this in mind when you ask yourself why you want to be friends? If it’s an attempt to hold on to a love lost, then it’s best not to delude yourself thinking that being ‘friends’ will make the break easier: it won’t. Don’t be ‘friends’ simply to ease the pain of the breakup. It will only prolong it.

2. If you decide to be friends, take ‘Time Out’ to give each other space to end the old relationship and start a new one – as friends. This will usually be anywhere from 3 months to a year, depending on the depth and length of your relationship.

3. If children are involved, like in Reese and Charlie’s splits, then of course you need to make a big effort. The prefect examples are Bruce Willis and Demi Moore who serve as great role models of staying friends with an ex. They put aside their differences in order to come together and provide solid parenting.

4. And if you’re still in love with them, then, no matter what you think, you are not ready to be friends yet. You might never be.  And that’s ok. Make sure you’re honest with yourself about this, so you can leave the relationship in the past in order to move forward in your life.

5. Whatever you decide, try and see the relationship for what it was. Remember the good in it, or at least what you’ve learned about yourself from it. My take is that if you can end love well, you’ll be able to do begin new love well too!