Should I keep dating this boy?

So I've been seeing this guy for 5 months, and he was very sweet and charming in the beginning. He took my out to nice restaurants, said sweet things, and was overall very nice to be with. However, recently I've noticed his mood has changed and he keeps pushing (not sex) but to go further with making out than I want to. Also he was at a party with me recently and was not only non sociable but also very possessive, which my friends and I quickly noticed. Any advice? Thanks in advance! =)