Anna: People get defensive when they're hiding secrets so if you ask him where he was and if he gets all defensive and he goes all "why are you asking me this? You never asked me this before??? What's wrong with you? Are you on your period or something???" or if you know the girl he's cheating with and you mention her name and he either changes the topic immediately or becomes defensive again, then you have a pretty good reason to think that he's cheating on you. However, if you feel that he's just neglecting you and stuff like that, then you're gonna need more proof. But the ultimate way to find out without destroying his trust is to ask him himself, as gently as possible.
Reign: Try to ask him how his day went and/or who he was with, if he reacts different from how he would normally react, then that says something. You could always ask him straight if he's cheating on you, but there might be a chance that he'd deny it even if it were true. You can also ask his friends or the people around him on a daily basis if he's hanging out with another girl. If you think you're just being paranoid, maybe give it a little more time. The next time something suspicious happens, that's when you "attack".
"My parents don't like the guy I'm dating but I really like him. What can I do to change how my parents see him?"
Anna: Are you sure they don't like him for the right reasons? I mean when you're in love, you can't see anything at all - except that person's good side. So, evaluate first if your parent's reasons are actually valid for not liking him. If they are, then start rethinking why the hell you're with the guy. If they aren't, then just explain to your parents why like him or just tell them his bank statements. I'M KIDDING. But seriously, talk to them. Explain to them, and tell them you love/like him for all the good reasons.
Reign: Remember that your parents are always looking out for you and they want you to have the best of everything. Surely there's a good enough reason as to why they don't seem to like him. Parents can be very overprotective when it comes to their children dating, so ask them why they think about him that way. If your parents don't like him because of petty reasons like he's not handsome enough or he's not rich enough, then tell your parents that you like him because of (insert some of his likable characteristics here) and not because of how he looks or whatnot. It can be really hard to force your parents to change what they think of him, but as you said, you really like him. So it shouldn't matter what they think.
"I think my boyfriend is actually gay. How can I know for sure without hurting his feelings?"
Anna: First of all he could be bisexual. There's nothing wrong with dating a guy who likes guys just as long as he likes you more. But if you have a feeling he doesn't, just have a nice chat with him. I mean, there's nothing wrong with that. You're gonna clear up all the misunderstandings and you get to have a new gay best friend!
Reign: This is so hard because if he isn't gay, and you ask him if he is, then things will get messy. Maybe he's just more in-touch with his feminine side; or as I always say, you could always blatantly ask him. If he says no, then that's a good thing. If he says yes, then at least you've cleared things up. Don't leave him if he were gay, okay? I mean, yes you can call it off, but I do hope you continue to be friends with him. Personally, it wouldn't be nice if you were to break up with him and never speak to him again just because you found out that he's gay.