When he wants to be with you forever, an Aries guy will demonstrate it. He'll pamper you. He grows closer as the connection matures.
Taurus boyfriends are sensible and traditional, so if they see your needs are different from theirs, they'll recognize that even if they want to stay with you forever, it won't work.
Gemini guy can't stand boredom and requires constant adrenaline, but when he meets someone he's serious about and who has everything he's been looking for
If you want to know if your Cancer lover wants to marry you, ask his parents first. Cancer boyfriends never hint at marriage or proposals.
He'll say, "We're going to be together forever," while walking the dog or grocery shopping, and you'll merely nod.
He's a serial monogamist because he feels if you're in a relationship, you'll never be lonely. He can cope without his forever person, but he hopes it never happens.