(Feel free to start seating Group 2 while you serve the Chucks. Just don't take their gifts, or you will break both the food chain and the gift chain!)

Leave Chloe seated until seating Al [Chloe] and Diane [Chloe] with Group 3.

If you need to, leave Derek seated at the Flower Table until seating Allison [Derek] with Group 3. (There will be another Derek in Group 3, but Allison may be getting irate.)

Seat Chuck [Heart Table] in the middle of the Heart Table, serve him, and get rid of him. Replace with Diane [Heart Table].

Note:  The game likes to give me at least one reseat request I can't fill in this Group... if this happens to you, then it's your choice: Pick up the offending guest and drop him/her right back down to get rid of the request, or ignore the request until you can fill it (which may not be until everyone else has been served cake).