Dad on viagra

My dad is 48 years old and my mom is 47. My parents don't have a good relationship. They don't sleep in the same room. The other day I found Viagra pills in his drawer does that mean he's cheating on my mom?

Noel's response

Even though he and your mom don't sleep together, it is possible they have sex from time to time, and if they do, he may find it necessary to use viagra, because of the emotional difficulties between him and your mom.

If they do not have any sexual relationship, it does look suspicious.