He is very open about his feelings.
He will pay you surprise visits with small gifts.
He forgets about his worries in your company.
He stops flirting with everyone else.
Asks questions about your future plans.
He shows you his vulnerable side.
He proposes solutions to your problems.
He starts texting with details from his life.
He involves you more and more in his plans.
You can see he puts effort in making you room in his life.
He has an approachable and intuitive flirting style