Pregnant, tired and horny

Hi, I'm 23. 23 weeks pregnant and I'm tired early at night so I go sleep between 8 and 9pm. My fiance is a night owl he goes to bed after 2am.

I get horny and I'm not sure how to initiate sex, should I just go sit next to him and tell him I want some?

He said I should seduce him but I'm not sure what that even means??? Can it be done without lingerie? PLEASE HELP!