When a guy starts using the word love towards you for example if he says I love your chubby tummy, is he wanting something serious or a fling?

loving something about how you look is not an expression of romantic love.
He probably would like to go to bed with you, though; would you like to go to bed with him, if romantic love or exclusivity are not involved?

Depends. Is he just saying he loves certain things about you (like your chubby tummy), or you as a whole?

I can’t speak for all guys, but as a general rule, I won’t tell a woman I love her until we’re already exclusive.

Sounds like he just wants to have fun. Be a bit careful with this one