tell her how responsible you are
You can't convince him not to break up with you, it's his decision and his feelings.
... If you have a boyfriend, pregnant.. Wouldn't it be best to stay with him? O.o
Tell them, it's better than an older boyfriend. Ask the age difference between your parents and relate it to you and your boyfriend.
you have to ask him to go to a quiet closet and then do it.
If you are not at least twenty years old, you will not be able to convince them because they were young once and they know you have to be a certain age before you can really be able to tell the difference between love and infatuation. If you have to convince your parents, you are not mature enough. When the time comes, you will only have to convince yourself.
If the girl in question likes you then you won't need to convince her to let you be her boyfriend, you must wait for the signs to see if you think she is interested, let the girl make the move, don't be pushy, be patient.
You would have to ask your boyfriend why he won't give you a place to stay. Maybe your boyfriend doesn't have room for you to stay with hi or doesn't have a place for you to stay. He may not be ready to make a biog commitment.
don't try and convince her, just let her choose, because really its her decision and its really low to try and talk down about her bf and she might take it personal
Stay faithful
Tell him, "If I had feelings for him, I'd be his girlfriend.
You prove it to him. You don't just say it, do it.