While consenting adults may have sex for any reason, it's best to be honest with partners about motives to ensure everyone leaves the engagement with good feelings.
More About Pity Fuck
Although there is no real data on how many people choose to have sex this way, there are plenty of anecdotal stories of people who gave a pity fuck. Some of the reasons include that the person was a virgin, was insecure about sex, was sad and needed comforting or was unattractive in some way.