Definitely Lucas. Just think about all the times that he surprised her, with romantic things:
- Surprising her in in LA, and proposing
- HIM deciding that getting married in Vegas wasn't a "dream come true"
- Framing the "nice hands, nice legs" drawing during their little battle in the house
- Bringing her a rose after finding out she was pregnant
- Taking her to their spot to officially give her an engagement ring
- Decorating the nursery
- Decorating the house for their wedding night
- Fixing the comet for her
- Writing two books about their love

^Agree.