Heidi Klum and her ex-husband Seal exchanged pleasantries -- and a cheek kiss -- in public over the weekend ... the first time we've seen them together since their nasty split last year.

The two came together in Malibu this weekend to celebrate their daughter's 4th birthday ... and nearly 2 years after they split, it seems they've finally decided to play nice.

As we reported, Heidi separated from Seal in January 2012 and filed for divorce in April. Heidi's story was that she couldn't handle Seal's explosive temper.

After the split, Seal accused Heidi of banging her bodyguard during their marriage and alleged that's why they broke up. It was pretty bad.

But now, it seems that's all water under the bridge.

Heidi Klum, the world famous model was married to Seal for 7 years, she even had a tattoo, that she just recently got removed due to the split.