When saying/singing “滅する希望/metsu suru kibou” do you pronounce つ and す as separate or just combine them?

I was listening to Corpse Attack, by Utsu-P, and I noticed that even though the romaji version say the lyric is "metsu suru kibou", it sounds like it's pronounced in the song as "messuru kibou" like, omitting the double "tsu/su" sound. Is this accurate? Like is this a thing they do in Japanese, where it's redundant to say the sound twice? Or am I just mis-hearing the lyrics? I've been dabbling in learning japanese, and I hardly ever see weird quirks like this explained.