Of 18 months ? I can afford to and I don't need the money at the moment. He has had an unexpected but vital and necessary reason to need £3k.
He will repay over a long period, A year or two , and it is me who is thinking of offering as he has some savings but will need these for emergency funds.
Using his savings will mean that he would not have much to fall back on if there was any major acute financial outgoing.
I don't earn on my savings and it is a way of putting away secret savings and not declaring them in divorce .
I trust him to repay, without question.