Two number 5s 五 , giving each other a reciprocal 69er!
they xzz each other. ★★★☆☆ 1/2 KANA
mutual, reciprocal. ★★☆☆☆ NP 相 (partner) + 互 (reciprocal) + 的 (motivation / '-al') = 相互的 (mutual, reciprocal.)
alternately ★★☆☆☆ 交 (combine) + 互 (reciprocal) = 交互 (alternately)