This is purely hypothetical having never been in the BA F cabin, but why not book 4 E/F then 5 E&F. The chap in row 4 can then kneel on their seat and chat - preferably loudly (whilst wearing his/her finest shell-suit) - over the back of his/her suite to those in row 5. For maximum effect, i'd suggest packing some watercolours, oh and of course drinking champagne in the lounge to boot.....