We all have things we do in the privacy of our own home that we don't tell others about.
But these quirky behaviours usually come to light when we let people get close to us.
Most of the time, it makes no difference, but occasionally that Taylor Swift admits strange shower habit - and it's sparked a gross debate can be a real turn off for a partner.
One man has found himself in this exact situation after discovering the 'gross' thing his girlfriend does and it's left him wondering if he should break things off.
Taylor Swift admits strange shower habit - and it's sparked a gross debate
The unnamed man revealed all in a letter to an agony aunt.
Writing in to Slate's Dear Prudence column, the man explained that his girlfriend has a strange habit involving mucus.
He said: "My girlfriend of four months, 'Lucy', has a really gross habit of coughing mucus up into her mouth so she can spit it out.
"She sometimes removes the mucus with her fingers and spreads it on a nearby surface (if we're outside). This happens when we're alone or in front of others."
Mum reveals her family's unusual toilet antics - and it's sparked debate
He claims to have spoken to her about it and told her of his concerns.
She in turn admitted that there's no medical reason behind her behaviour - it's simply something she does.
"I really like her," he adds. "I can see us getting serious. But the habit is grossing me out. Am I crazy for asking her to change a lifelong habit if we want to stay together? Would that make me too controlling?"
Prudence is quick to tell the man that it most certainly would not be "controlling" and advises his girlfriend to get a thorough check up from a doctor as it could be related to an underlying condition.
The agony aunt goes on to say: "Even if there's nothing else going on medically, pulling ropes of mucus out of your own mouth and wiping it on a wall is totally disgusting, totally unsanitary and totally voluntary. I am shuddering as I write this!"
