It made him feel indispensable and needed - even if the fact that Jocelyn didn't appear to care wheather he slept in her daughter's bed or not did underscore that Clary's mother apparently regarded him as about sexually threatening as a goldfish.
Until a man can quit talking loudly to himself in order to shout down the memories of blunderings and gropings, he is in no shape for the painstaking examination of distress.