Serial kisser?

I’ve been with my boyfriend for just over a year, we went away a month ago for a long weekend and he mentioned whilst we were there about how he and his ex used to play ‘kissing competition games’ on a night out, I said how I would never do that and think it’s really disrespectful. He then went weird on me and three weeks later, he’s effectively ended the relationship But with the option of me getting in touch after a break if I want too. His reason’s for breaking up were us being too different, the main being that I couldn’t ‘cope’ with him playing games, meaning when he goes on a night out and gets super drunk, he kisses other girls. It’s never lead to anything more but kissing, but I’m struggling to get past it and I’m not sure if it’s normal? Has anyone had any experience or advice on this? I’m so confused, I love him and it’s mad to think a month ago we were looking at houses together and now it’s finished! Any advice would be much appreciated!