@Sarah1798,
Relationships take a lot of work. Love is used so flippantly.
Does he smoke weed regularly? Do you think that's a good thing if he does? He's claiming that as the reason, so shouldn't there be a conversation about him stopping smoking weed full stop?
If you were speaking to your ex constantly but feel that this guy is better and so you should stay with him, then can you really state you are in love?
If he is finding other girls attractive (smoking or not), then can he claim that he is really in love?
Or could it be that you've been together for 6 years and both can't really let go, yet a lot of things has passed in this relationship, can you get those things back?
In-other-words. You both need to really establish if there is a future for you both and things are a bit stagnant and can be worked on, together. Or if that used by date really has occurred and it's time for both of you to move on.
Morals stop you from cheating, or lessons learnt stop you from doing it again, but "love" is only real if two people feel it totally.