Love triangle help me please?

I have been seeing this guy for around a year and a half, he is a bit of a rugby boy, he used to go out loads and party and even admitted he was a bit of a player in the past, but I still don’t trusy him he has lied to me about a few things he went to a party with his mates and said he was staying over one of his mates houses but turns out they all stayed at this girls house, he said there was only girl there but I don’t believe him as I saw photos of them out and there were other girls there but he still denies it saying they were just randoms. He can be possesive and aggressive but does that show he cares? When we argue its very intense and he has punched things before like the wall etc but when we are getting on he is really lovely and caring. We see each other almost every day maybe 2 or 3 days off a week.The other guy I have known for around the same time we don’t see eachother as often, but we regularly go out for drinks with the same group of friends and he is the opposite of the first guy, he is calmer and very sweet and I can see he cares for me a lot he is a 'nice' guy and when together there is electricity. But I don’t know if this is because we don’t see eachother as much as I see the other guy or if its just lust (how do you know the difference between lust and love?)