Questions: Relationships

So my boyfriend saw a group photo and found my colleague looking better than me and he asked me her name and later on when I said that a colleague of mine is resigning so he asked me if it’s the same girl and also he asked me where is she going or joining and how is she doing and I feel that my boyfriend has a crush on her. Does this mean I should break up with my boyfriend? I asked him why he wanna know about her he said just like that - is my boyfriend toxic? Does this indicate that in future he is likely to cheat on me with someone better? Now we both have shared with each other our Instagram password and Recently from my Instagram, he opened her chat which u had unopened since past 3-4 days. It means he is checking her Instagram out for seeing her photos etc. So I’m really annoyed now. Does this indicate that my boyfriend does not really love me?

Our dog is a mutt/ pitbull mix looks like the picture his name is dodge he's a year and a half. We rescued him from a shelter after being returned for being "too destructive" we've had to make many changes to how we secure the house before we leave so he doesn't destroy things. My boyfriend Steven trains him (he's a first time dog owner) he teaches him basic commands and a bit more but this dog has attacked 2 dogs, wants to kill my pet kitten. Sometimes mistakes small children for animals, I want the mutt gone. People shouldn't be afraid of him, he just has that energy. My boyfriend doesn't want to rid of this dog at all he's extremely attached like he birthed dodge himself. He makes so many excuses the dog can chew off my arm and he'll probably reward him. He spends x amount of money on toys yet can save 250 to buy lessons. We have him on 400mg of trazadone and he's still psycho. Wwyd? My boyfriend is stubborn and will absolutely not let this dog go, I just want to be able to walk around my neighborhood without tearing for others dogs and possibly children.