Men are always looking for sex! In my personal Experience
Young guys between 15- mid 20's can have erections (can cum) 4-6 times in a day
In early 30's its still on but goes down to 2-3 times in aday
In early 40's 1-2 times in a day.
So I would say its normal and one should not overeact. Maybe talk to him and you both can enjoy together.