How do i know if this guy likes me im 21 he is 18 might have a girlfriend but latley he laughs when i laugh tell me things that he might not tell any one else but his mom but when i told his mom and she dont care is it weird what should i do?

If I were you I'd totally believe he likes me, I mean he laughs when you laugh and all these things, I mean this shows that he's interested in you. If he wasn't he wouldn't even be around you, but before you fall you have to notice if he spends more time with you and you have to make sure there's nothing you can doubt about his love for you before you get dissapointed, it hurts so much when it turns out your expectations are wrong, especially when it comes to love, it always happens to me, so be careful!