I have never been in your situation, so I honestly don’t know what the right course of action is, but you’re very kind and considerate to want this connection. When wedding planning gets under way, reach out to his mother for her opinion. (Moms love this.) Invite his parents to every event, and after every gesture that they make toward you, send a hand-written note and flower arrangement to say thanks. Forge bonds slowly and with care; you have the rest of your life to bond with his family, so don’t rush things right out of the gate.
Married FrED fans, is this a decent response? What would you do?