Since we are apparently on this topic, I suppose a few words about German
'ficken' / English 'fuck' are in order.
I think an easy way into the study is noticing PIE *(s)pingo-, 'sparrow,
finch', which I will interpret as 'pecker' (incidentally a slang English word
for 'penis') for reasons explained below.
This is derived from the Pokorny entry *(s)p(h)e/e:i-, 'pointed', IMHO.
I think this word should be reconstructed as *p(h)eing^- (English 'fink'),
and has as a basic underlying idea 'poke' (an English slang word for 'fuck').
So, somebody who is poked gets angry; and a related set of meanings has
'angry/inimical', the natural reaction to 'poking'.
Egyptian has bq, 'be hostile', which may be related if bq really should
read b(j)q.
Patrick