We usually avoid like the plague, any reference to ‘shameful’ body parts. This is one small exception. Please excuse the (direct and) implied crudities.
Sayings with reference to one’s rear end!
‘She has a face on her like a well-skelped a**e’
Not dissimilar to .. ‘a face on her like wan chewing wasps!’
‘Here’s me head: me a**e is coming!’
This latter was often said, even in my youth, of those who walked bent-forward!
‘He’s running around like a blue-a**ed fly!’
‘Ye’re as bad as Yella Kate who showed her a**e to the train!’
This particular Kathleen was espied from a passing train, relieving herself in the bushes! Said of one walking about the house less than fully-clothed!
‘He’s not worth the full of me a**e of green gooseberries’ [I don’t rate him highly!]
‘He doesn’t know his a**e from his elbow’ – as above!
The Pahvee boasted of the special properties of the cloth he sold:
‘It’ll wash like a child’s a**e, and wear like a woman’s tongue!’
The modern woman who asks rhetorically, ‘Does my bum look big in this?’ would have had short shrift in times gone by!!
‘She’s an a**e on her like a
Alternative comparatives included .. like the back of a bus! .. like our house!’
A less critical expression relating to a man with a small bum!
”He’s an a**e on him like two eggs in a handkerchief!’