夏天说他爱西瓜西瓜说她爱夏天
[xià tiān shuō tā ài xī guā xī guā shuō tā ài xià tiān]
Translates directly to 'Summer said He Loves Watermelon, Watermelon Said She Loves Summer,' which might imply a cute and whimsical relationship or simply a lighthearted affinity towards summer pleasures such as eating watermelons.