dirty Meerkat
When participating in Al Fresco sex -preferably in a meadow - and the girl is on top, she pauses - sits up straight and looks around sharply to check for any pervy dog walkers/ramblers/cyclists/hot air balloonists in the manner of a meerkat checking for danger.
Basil and Sybil were getting some afternoon delight in the meadow, Sybil climbed aboard and got down to it - then suddenly sat bolt upright in the Dirty Meerkat position when she heard a rustle in the hedgerow....