Think a close friend of mine is gay and need some advice

So my friend who I've been in close relation to over the past year and a half has shown some signs he may be bi over the past few months. Sometimes when we hang out and are well turnt, don't judge, I would hold his hand and he'd not only let me hold his hand but he would like carress it I guess. I don't know the word for it but basically hold hand and intertwine them or I have no clue how to explain it.Another thing he's let me do is get very close to him. Like pretty much kissing distance and he wouldn't so much as flinch or tell me to back off.But that was months ago with no other signs until recently where I feel he's used a sort of more, flirtatious or just different way of texting me. I don't haveany of them saved, thanks Snapchat, but on the weekend he called me baby at the end of our text message.And I don't think too much of this one but his mom said awhile ago during a conversation "Now I see why you love him." If he's straight then its probably just a love hanging out/having over type of thing as opposed to romantic nature,So if he is bi then his recent new mannerisms mean he's slowly coming onto me and I feel like hes doing this to kind of drop the hint that he likes me.If I'm not just over thinking this or being a lovestruck idiot then what can I do to kind of send the message that I like him and am interested? Like I want to sort of send hints but if he is straight I don't want to scare him off and not be friends anymore.