、？
Ouch — was our relationship really that cold?
Literal
Cruel [confirm-ね], we [gen-の] relationship [topic-は] this-much dry [copula-だった] [nominalizer-の]?
ドライ is the English loan 'dry' used figuratively for 'emotionally cold / detached / unsentimental' — a very common metaphor in Japanese that has fully displaced any physical reading in this context. ヒドイ is the katakana rendering of 酷い, chosen for emphatic tone. The ending ~だったの? (with rising intonation) is a confirmatory 'was it really?' question. こんなに 'this much / to this extent' functions as an intensifier.