Am I a bad person? Should I stop now before it goes too far?

I've been feeling really taken for granted by my boyfriend recently. He's rude to me and makes me feel kind've inferior by acting like he's smarter than me all the time and he's always making excuses not to hang out with me but will instantly go out if someone else asks him to even if that person is with me. I've spoke to him about it many times but it still seems to continue, I don't know whether he's doing it on purpose or he genuinely doesn't realise but he's just acting really selfish constantly. I love him so much and can't bring myself to hurt him and end things or take a break. Recently I've been talking to this guy and it's got flirty and I'm kind've enjoying it because he's actually appreciating me, he's asked for pictures and I haven't sent any. Would it be bad if I did? I know he's using me in a way but we are good friends and have been for a while and he's made it very clear he's not interested in a relationship and swears he'll keep it a secret. Is it bad for me to even consider this? Honestly I'm feeling like a pretty shitty girlfriend but at the same time I'm kind've liking the idea. Honest answers please.