いきなり の訳語→ abruptly beginning bluntly directly fast freely instant instantly leap new out-of-the-blue outright point-blank pointblank promptly sudden suddenly unannounced violently
だしぬけに の訳語→ immediately surprisingly unexpectedly
思わず の訳語→ automatically briefly inadvertently instinctively involuntarily unconsciously unintentionally unwillingly visibly
反射的に の訳語→ gut reflectively