Novels like One Hell Of A Vacation

All share First Contact and Multiple Lead Characters

Destiny Among the Stars -

Also Romance Subplot

Diving the Blue

Also Romance Subplot

Hero by Design: The Old God's Game

Also Romance Subplot

I CLIMB (A Progression/Evolution Sci-Fi Novel)

Also Romance Subplot

Princess of the Void: An Alien Abduction Romance

Also Romance Subplot

New York Carnival

Also Romance Subplot

Tales of Eleutheros

Also Romance Subplot

Of Men and Spiders

The Last Human (Series Complete)

The Terran Empire

Also Romance Subplot

Also Romance Subplot

This Necromancer Raised Civilization Instead of the Dead