Most Helpful Guy
How does he look at you ? That's the first question you should ask yourself. The best indicator of a true love-like feeling are those random looks we sometimes give and then shrug off slightly embarassed. If he has to refrain a smile when he watches you perform the most basic task, if form a moment he just feels the need to stare into your eyes... That is how you know if he loves you, words are cheap, and actions are for the most unreliable, looks betray thoughts.
Secondly, his frendliness towards girls seems strange, was alcohol involved in those stories ? Were these girls aware he wasn't single ? At any rate these actions don't mean anything about how he feels, they only describe how he acts EVEN WHEN he feels. Therefore you could try to change him, or accept that you don't like him, if even in love he can't resist other girls then that's a character flaw and it's up to you to decide wether it's bearable or not.