Isekai Affair: 10 Years After Defeating the Demon King, the Hero Cheats on His Wife with a Warrior Woman Who Lost Her Husband Vol. 2 (manga)

Being heir to the throne and married to a princess would be enough for most people. But Yuuta, the legendary hero who defeated the Demon Lord, discovers that the only thing that gets his heart racing anymore is sneaking behind his family’s back to sleep with his party member, the warrior Luca. But what happens when their rendezvous turns out not to be as secret as they thought? Will their unexpected onlooker spill the beans to the princess?